Untitled

import java.util.Scanner;

public class StringMethodsDemo {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        boolean continueProgram = true;

        while (continueProgram) {
            System.out.println("Enter a string:");
            String input = scanner.nextLine();

            System.out.println("Choose an operation:");
            System.out.println("1. Convert to Uppercase");
            System.out.println("2. Convert to Lowercase");
            System.out.println("3. Find character at a specific index");
            System.out.println("4. Check if the string contains a substring");
            System.out.println("5. Compare with another string");
            System.out.println("6. Trim the string");
            System.out.println("7. Get the length of the string");
            System.out.println("8. Replace characters in the string");
            System.out.println("9. Split the string by space");

            int choice = scanner.nextInt();
            scanner.nextLine(); // consume the newline after the number

            switch (choice) {
                case 1:
                    System.out.println("Uppercase: " + input.toUpperCase());
                    break;
                case 2:
                    System.out.println("Lowercase: " + input.toLowerCase());
                    break;
                case 3:
                    System.out.println("Enter index:");
                    int index = scanner.nextInt();
                    if (index >= 0 && index < input.length()) {
                        System.out.println("Character at index " + index + ": " + input.charAt(index));
                    } else {
                        System.out.println("Invalid index.");
                    }
                    scanner.nextLine(); // consume newline
                    break;
                case 4:
                    System.out.println("Enter substring to check:");
                    String substring = scanner.nextLine();
                    if (input.contains(substring)) {
                        System.out.println("The string contains the substring.");
                    } else {
                        System.out.println("The string does not contain the substring.");
                    }
                    break;
                case 5:
                    System.out.println("Enter another string to compare:");
                    String anotherString = scanner.nextLine();
                    if (input.equals(anotherString)) {
                        System.out.println("The strings are equal.");
                    } else {
                        System.out.println("The strings are not equal.");
                    }
                    break;
                case 6:
                    System.out.println("Trimmed string: " + input.trim());
                    break;
                case 7:
                    System.out.println("Length of the string: " + input.length());
                    break;
                case 8:
                    System.out.println("Enter character to replace:");
                    String oldChar = scanner.nextLine();
                    System.out.println("Enter new character:");
                    String newChar = scanner.nextLine();
                    System.out.println("Updated string: " + input.replace(oldChar, newChar));
                    break;
                case 9:
                    String[] words = input.split(" ");
                    System.out.println("Split words:");
                    for (String word : words) {
                        System.out.println(word);
                    }
                    break;
                default:
                    System.out.println("Invalid choice.");
                    break;
            }

            System.out.println("Do you want to perform another operation? (yes/no)");
            String continueResponse = scanner.nextLine();
            if (!continueResponse.equalsIgnoreCase("yes")) {
                continueProgram = false;
            }
        }

        scanner.close();
        System.out.println("Program terminated.");
    }
}